Light-reflecting bodies (reflectors) are known to be used for reflecting light emitted from a light-emitting element, such as a light-emitting diode. One of known resin materials used for manufacturing light-reflecting bodies is unsaturated polyester resin. Unsaturated polyester resin includes unsaturated polyester (alkyd) and cross-linking agent, such as styrene. The use of unsaturated polyester resin, which is thermosetting resin, increases heat discoloration resistance of the light-reflecting body.
For example, PTL1 discloses fabrication of an LED reflector by molding unsaturated polyester resin composition containing unsaturated polyester resin and white pigment. This unsaturated polyester resin includes unsaturated polyester, co-polymerizable monomer or oligomer, and thermosetting resin. Still more, PTL1 refers to melt and heat molding methods, such as injection molding, injection compression molding, and transfer molding.